Sean's series The Biggest Ideas in the Universe has some merit, but it's just to math-light falling a bit below the missing link between basic and advanced.
Webpack is like a magic hydra that can eat any type of file and bundle it into a single output: .js, .ts, .ccs, .scss, .jsx, .tsx,
require, import, import css from .js, it doesn't matter at all, it just digests all into the same dump.When it works, you are just left in awe and with a single Js file. When it doesn't, you're fucked and have to debug for several hours.
Demos under: webpack/. To run all of them by default:To easily make changes and reload the .js output live let this run on a terminal:
cd webpack/min
npm install
npm run build
xdg-open index.htmlnpx webpack watchExamples:
- webpack/min: minimal hello world. Doesn't do much, just copies
index.jstodist/index.js. - webpack/require:
requireandimportdemo. Both work from the same file.dist/index.jsnow contains all of:notindex.jsnotindex2.js- Lodash, a common third-party helper library specified in the package.json and installed with npm
- webpack/node: produce Node.js output, as opposed to the default web output. To test it run:Achieved simply with:
npm run build node dist/index.jsas documented at: webpack.js.org/concepts/targets/target: 'node'Fatman in Robin, - webpack/sequelize: attempts at getting Sequelize to work with webpack. It's just not supported by Sequelize:
Some nice insights at: Robert Noyce: The Man Behind the Microchip by Leslie Berlin (2006).
Since DNA is the centerpiece of life, Ciro Santilli is extremely excited about DNA-related technologies, see also: molecular biology technologies.
The exact format of table entries is fixed by the hardware.
The page table is then an array of
struct.On this simplified example, the page table entries contain only two fields:so in this example the hardware designers could have chosen the size of the page table to b
bits function
----- -----------------------------------------
20 physical address of the start of the page
1 present flag21 instead of 32 as we've used so far.All real page table entries have other fields, notably fields to set pages to read-only for Copy-on-write. This will be explained elsewhere.
It would be impractical to align things at 21 bits since memory is addressable by bytes and not bits. Therefore, even in only 21 bits are needed in this case, hardware designers would probably choose 32 to make access faster, and just reserve bits the remaining bits for later usage. The actual value on x86 is 32 bits.
Here is a screenshot from the Intel manual image "Formats of CR3 and Paging-Structure Entries with 32-Bit Paging" showing the structure of a page table in all its glory: Figure 1. "x86 page entry format".
The fields are explained in the manual just after.
As of December 2023, the cheapest instance with an Nvidia GPU is g4nd.xlarge, so let's try that out. In that instance, lspci contains:so we see that it runs a Nvidia T4 GPU.
00:1e.0 3D controller: NVIDIA Corporation TU104GL [Tesla T4] (rev a1)Be careful not to confuse it with g4ad.xlarge, which has an AMD GPU instead. TODO meaning of "ad"? "a" presumably means AMD, but what is the "d"?
Some documentation on which GPU is in each instance can seen at: docs.aws.amazon.com/dlami/latest/devguide/gpu.html (archive) with a list of which GPUs they have at that random point in time. Can the GPU ever change for a given instance name? Likely not. Also as of December 2023 the list is already outdated, e.g. P5 is now shown, though it is mentioned at: aws.amazon.com/ec2/instance-types/p5/
When selecting the instance to launch, the GPU does not show anywhere apparently on the instance information page, it is so bad!
Also note that this instance has 4 vCPUs, so on a new account you must first make a customer support request to Amazon to increase your limit from the default of 0 to 4, see also: stackoverflow.com/questions/68347900/you-have-requested-more-vcpu-capacity-than-your-current-vcpu-limit-of-0, otherwise instance launch will fail with:
You have requested more vCPU capacity than your current vCPU limit of 0 allows for the instance bucket that the specified instance type belongs to. Please visit aws.amazon.com/contact-us/ec2-request to request an adjustment to this limit.
When starting up the instance, also select:Once you finally managed to SSH into the instance, first we have to install drivers and reboot:and now running:shows something like:
- image: Ubuntu 22.04
- storage size: 30 GB (maximum free tier allowance)
sudo apt update
sudo apt install nvidia-driver-510 nvidia-utils-510 nvidia-cuda-toolkit
sudo rebootnvidia-smi+-----------------------------------------------------------------------------+
| NVIDIA-SMI 525.147.05 Driver Version: 525.147.05 CUDA Version: 12.0 |
|-------------------------------+----------------------+----------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
| | | MIG M. |
|===============================+======================+======================|
| 0 Tesla T4 Off | 00000000:00:1E.0 Off | 0 |
| N/A 25C P8 12W / 70W | 2MiB / 15360MiB | 0% Default |
| | | N/A |
+-------------------------------+----------------------+----------------------+
+-----------------------------------------------------------------------------+
| Processes: |
| GPU GI CI PID Type Process name GPU Memory |
| ID ID Usage |
|=============================================================================|
| No running processes found |
+-----------------------------------------------------------------------------+If we start from the raw Ubuntu 22.04, first we have to install drivers:
- docs.aws.amazon.com/AWSEC2/latest/UserGuide/install-nvidia-driver.html official docs
- stackoverflow.com/questions/63689325/how-to-activate-the-use-of-a-gpu-on-aws-ec2-instance
- askubuntu.com/questions/1109662/how-do-i-install-cuda-on-an-ec2-ubuntu-18-04-instance
- askubuntu.com/questions/1397934/how-to-install-nvidia-cuda-driver-on-aws-ec2-instance
From there basically everything should just work as normal. E.g. we were able to run a CUDA hello world just fine along:
nvcc inc.cu
./a.outOne issue with this setup, besides the time it takes to setup, is that you might also have to pay some network charges as it downloads a bunch of stuff into the instance. We should try out some of the pre-built images. But it is also good to know this pristine setup just in case.
We then managed to run Ollama just fine with:which gave:so way faster than on my local desktop CPU, hurray.
curl https://ollama.ai/install.sh | sh
/bin/time ollama run llama2 'What is quantum field theory?'0.07user 0.05system 0:16.91elapsed 0%CPU (0avgtext+0avgdata 16896maxresident)k
0inputs+0outputs (0major+1960minor)pagefaults 0swapsAfter setup from: askubuntu.com/a/1309774/52975 we were able to run:which gave:so only marginally better than on P14s. It would be fun to see how much faster we could make things on a more powerful GPU.
head -n1000 pap.txt | ARGOS_DEVICE_TYPE=cuda time argos-translate --from-lang en --to-lang fr > pap-fr.txt77.95user 2.87system 0:39.93elapsed 202%CPU (0avgtext+0avgdata 4345988maxresident)k
0inputs+88outputs (0major+910748minor)pagefaults 0swapsHow genes form bodies.
Developmental Genetics 1 by Joseph Ross (2020)
Source. Talks about homeobox genes.Contains the genes: e. Coli K-12 MG1655 gene thrL, e. Coli K-12 MG1655 gene thrA, e. Coli K-12 MG1655 gene thrB and e. Coli K-12 MG1655 gene thrC, all of which have directly linked functionality.
We can find it by searching for the species in the BioCyc promoter database. This leads to: biocyc.org/group?id=:ALL-PROMOTERS&orgid=ECOLI.
That page lists several components of the promoter, which we should try to understand!
Some of the transcription factors are proteins:
After the first gene in the codon, thrL, there is a rho-independent termination. By comparing:we understand that the presence of threonine or isoleucine variants, L-threonyl and L-isoleucyl, makes the rho-independent termination become more efficient, so the control loop is quite direct! Not sure why it cares about isoleucine as well though.
Exams as a prerequisite for a degree are useless. Exams as part of a degree must be abolished. And degrees must be abolished. Ultimately the only metrics that really matter are money and fame. See also: motivation.
The only thing exams should matter for is as a screening tool to select people with specific abilities that you care about as an employer or principal investigator. If:then exams are useless for your purposes. then might as well just go by interviews (basically what all employers do already, though not PIs). Degrees are too course grained to mean anything to anybody. Employers and PIs likely only care about very few specific subjects.
- you have no idea about what the content of specific exams are (and you don't because they are all ad-hoc university secrets)
- or don't have a way to machine learn what grades correlate with your desired performance (you don't because where's the data?)
Once the question of an exam has been formulated, the usefulness of the problem is already been completely destroyed, because formulating the problem that matters is the most important part of things. And any problem with an answer, is useless to put effort into: give answers.
Furthermore, preventing people from searching for answers while answering an exam, AKA preventing "cheating", also makes absolutely no sense. In the real world, we want people to find answers as quickly as possible! We should be teaching people how to "cheat"! What we should teach them instead is what a fucking license is, and what you have to do to comply with it.
And if you must absolutely have exams, they must be open to anyone who wants to applies. Then people have to pay to take the exam, with subsidies for "official course takers", who are spending 100x more anyways due to not living with their parents.
And those exams must be applied by professional test application companies to ensure no cheating and to factor out the anti-cheat work, while still making the tests available to people anywhere.
A quote from Richard Feynman present in the book Surely You're Joking, Mr. Feynman chapter O Americano, Outra Vez!:
The only metric that matters is "to feel that you've satisfied youre curiosity". When one studies for that, it can take a lot more time to actually learn everything, because it is sometimes not as clear when you should stop. But it is the only way to go deeper.
Quantum logic gates are needed because you can't compute the matrix explicitly as it grows exponentially by 
Ciro Santilli 40 Updated 2025-07-16
Ciro Santilli 40 Updated 2025-07-16One key insight, is that the matrix of a non-trivial quantum circuit is going to be huge, and won't fit into any amount classical memory that can be present in this universe.
This is because the matrix is exponential in the number qubits, and is more than the number of atoms in the universe!
Therefore, off the bat we know that we cannot possibly describe those matrices in an explicit form, but rather must use some kind of shorthand.
But it gets worse.
This is because knowing the matrix, basically means knowing the probability result for all possible outputs for each of the possible inputs.
But if we had those probabilities, our algorithmic problem would already be solved in the first place! We would "just" go over each of those output probabilities (OK, there are of those, which is also an insurmountable problem in itself), and the largest probability would be the answer.
So if we could calculate those probabilities on a classical machine, we would also be able to simulate the quantum computer on the classical machine, and quantum computing would not be able to give exponential speedups, which we know it does.
To see this, consider that for a given input, say and therefore when you multiply it by the unitary matrix of the quantum circuit, what you get is the first column of the unitary matrix of the quantum circuit. And
000 on a 3 qubit machine, the corresponding 8-sized quantum state looks like:000 -> 1000 0000 == (1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0)001, gives the second column and so on.As a result, to prove that a quantum algorithm is correct, we need to be a bit smarter than "just calculate the full matrix".
Which is why you should now go and read: Section "Quantum algorithm".
This type of thinking links back to how physical experiments relate to quantum computing: a quantum computer realizes a physical experiment to which we cannot calculate the probabilities of outcomes without exponential time.
So for example in the case of a photonic quantum computer, you are not able to calculate from theory the probability that photons will show up on certain wires or not.
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 3. Visual Studio Code extension installation.
Figure 4. Visual Studio Code extension tree navigation.
Figure 5. Web editor. You can also edit articles on the Web editor without installing anything locally.Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.Video 4. OurBigBook Visual Studio Code extension editing and navigation demo. Source. 
- Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact